My potatoes are rotting....

[clkeiper]

We have had 16 days of rain. 5 inches since last Saturday *double sigh*, but now that the weather is clearing up I see the one plot of potatoes ( mostly Red Norlands)is looking sad. I started to dig a few of them and they are rotting. Is this normal due to the excessive amount of rain we have had? Last summer's drought produced more than this summers well water garden. This garden seems a little clayish compared to my other plot. It was amended with leaves and chicken manure last fall, but I did not fertilize them this spring when I planted them or after that either. OR am I looking at a disease if the excessive water isn't what is causing it?

[Patihum]

I would think that it's probably because of all the rain. Were your plants still actively growing and green? If they were and showed no sign of disease before I'd double the chances that it's from all the wet.

[clkeiper]

Thanks, I just wanted another opinion. I haven't grown them for more than a couple years and haven't seen this happen yet. We normally don't have 16 days of rain in a row....The weeds are unbelievable. They either pull right out or break off like lettuce, but there are an extraordinary number of them...everywhere. I have kept these rather clean of weeds, but I think they are struggling due to the wet. It is rather disappointing as I have 2 50ft rows here.

[Mark0820]

I agree with the rain. My potato plants were nice and green with flowers just starting to bloom. After a good amount of rain, I am left with yellow and brown plants without much hope of a harvest. I didn't check under the soil, but I would imagine the tubers that started to form are rotting just like yours.

[Tom Wagner]

I lived in Kansas and Ohio and I remember the years of high rainfall in June/July and saying things like the idiom...

that it's from all the wet

I had many years experience breeding potatoes by the time I was sixteen back in Kansas and the year 1962 had 19 inches of rain during July at our farm south of Lancaster, Kansas. We couldn't get into the wheat field to harvest due to the rain...and the sunflowers were growing like the weeds they are. Cutting the darn things down in the wheat field was my job along with later on cutting the weeds with a corn knife in the milo and soybean fields.

Anyway...the ground was soggy from all the wet and the Pontiac potatoes were the worst...rotting in the soil. The Norlands, Coblers, Kennebecs, Early Ohios, were bad but not nearly as bad as the Pontiacs. Some of my seedling potatoes fared better but at the time I did not know why. The potatoes in wet heavy clay but black prairie soil stuck to the potato tubers and one had to lay them out to dry...but many didn't dry since they were rotting...what was the deal?

Looking back I know the problem was ....

Pink rot of potato, caused by Phytophthora erythroseptica, is an important storage disease of potatoes worldwide. The disease is usually associated with high soil moisture when tubers are approaching maturity and is a serious problem in poorly drained soils. Although the disease is predominantly found in wet fields it can also develop in sandy soils without excessive moisture.

Potato growers refer to the disease as "water rot" without distinguishing the pathogens involved. The name pink rot describes the pink color that develops in infected tuber tissue when tubers are cut and exposed to air for 15 to 30 minutes

Pink rot infection is usually associated with secondary infection by anaerobic soft rot bacteria

.

..diseased plants are first observed in poorly drained parts of the field. Disease symptoms, mostly characterized by stunting and wilting, appear on the potato vines late in the growing season. Wilting starts from the base of the stem and progresses upwards causing leaf yellowing, drying and defoliation. Vascular discoloration and blackening of the underground stems may also be observed. Similarly roots may turn brown to black in color and occasionally aerial tubers may develop.

Those experiences from all those years ago in Kansas have led me to life time search for rot resistant potato varieties. According to a Cornell study of tubers given to them a few years ago...I have some of the best Pink Rot resistant varieties found anywhere...especially my Nordic October....and red potatoes are notorious for Pink Rot susceptibility.

I continue to test for rot resistance by allowing many of my varieties to undergo storage in situ all winter. Those coming out the wet soil here in Western Washington have to have remarkable tolerance to "wet rot" and I keep finding new clones for breeding due to that tolerance.

Not much I can say to help anyone with the rot problem but remember to hill up the potatoes to keep the tubers above the standing water zone.

[clkeiper]

Originally Posted by Tom Wagner

Not much I can say to help anyone with the rot problem but remember to hill up the potatoes to keep the tubers above the standing water zone.

Thanks for your input too. I value all of it highly.
I was afraid to plant them and hill them up. After last year of rain once during the Summer, I dug a trench and planted them deeper than "standing water level, which would be non existent in this area, but there are springs in the ground in the back yard", but this is a garden on a slope and I have seen so much water from the rain that it actually was eroding the soil off enough to expose the tubers. So, no matter what I did this year it wasn't a good fit for the weather. As to the pink rot, I don't believe there is a change in the color of the potato out in the open air, they are all just rotty.

[wingnut]

I found I am having this problem in a wet area near an irrigation leak. Luckily only lost a few.

[wingnut]

They were reds.

[TZ-OH6]

I planted shallow this year and so hilling put the bottom of the trenches below the tuber zone. My fingers are crossed. Some brussels sprouts at the end of a row wilted but they were on the down hill side of the row. I know where I need another drainage ditch though.